Injector

ABSTRACT

An injector for delivering fuel to fuel inlets of a combustion engine. Two pump chambers which communicate with a fuel supply and with the fuel inlets are adjoined by a displacing member which is displaceable to and fro over a pump stroke between two adjustable common stops in order to deliver equal fuel amounts to all cylinders of the engine.

United States Patent 1191 Brinkman Dec. 24, 1974 [54] INJECTOR 2,053,543 9/1936 Vincent 123 139 AM 2,720,344 10/1955 Isreeli et al 123/139 AM [75] Inventor- Wlnem Bnnkman VelP 3,604,405 9 1971 Maker 123/139 AJ Netherlands 3,654,908 4 1972 Harding 123 139 AM [73] Assignee: Holec N.V., Steenbakkersweg,

- Netherlands Primary ExaminerWendel1 E. Burns [22] Filed: May 1, 1973 Assistant ExaminerD. D. Reynolds pp No: 356,185 Attorney, Agent, or Firm-Snyder, Brown and Ramik v [30] Foreign Application Priority Data [57] ABSTRACT May 5, 1972 Netherlands 7206081 I An injector for delivering fuel to fuel inlets of a com- [52] US. Cl.123/139 AM, 123/139 AJ, 123/139 AL, bustion engine. Two pump chambers which communi- 123/139 AW, 123/33 R Cate with a' fuel supply and with the fuel inlets are ad- [51] Int. Cl F02m 47/02 joined by a displacing member which is displaceable [58] Field of Search 123/33 R, 33 C, 139 A], to and fro over a pump stroke between two adjustable 123/139 AL, 139 AM, 139 AW common stops in order to deliver equal fuel amounts to all cylinders of the engine. [56] References Cited UNITED STATES PATENTS 15 Claims, 4 Drawing Figures 1,314,561 9/1919 Wright .1 123/139 AJ PATENTED [153241974 SHEET 1 [1F 3 INJECTOR The invention relates to an injector for delivering fuel to at least two fuel inlets of a combustion engine with at least two combustion cylinders, comprising at least two pump chambers, each of said pump chambers communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to a fuel inlet of the combustion engine and each of said pump chambers being adjoined by a displacing member being displaceable to and fro over a pump stroke between two stops, said pump stroke being adjustable by means of control means.

Such injector is described in the U.S. Pat. application No. 240.470, of Bernard Bruekink flled on Apr. 3, 1972 commonly assigned, now U.S. Pat. No. 3,828,748. I

With the known injector each displacing member is movable between a fixed stop and an adjustable stop, consisting of a screw being adjustable by control means on behalf of controlling the pump output. Mounting said injector so that all pump chambers in each cycle deliver accurately equal fuel volumes, is very difficult. Moreover, it is difficult with the above injector to arrange the pump output in dependence on more than one factor, influencing the motor output. It is the object of the invention to make accurately equal the fuel volumes delivered by all pump chambers per cycle and to provide simple mounting of the injector and adjusting the fuel output of the injector in dependence on more than one factor influencing the output of a fuel motor. To that aim the invention improves the injector for delivering fuel to at least two fuel inlets of a combustionengine with at least two combustion cylinders, comprisingat least two pump chambers, each of said pump chambers communicating via an inlet valve with a fuel supply and via an exhaust valve with a'fuel discharge to be connected to a fuel inlet of the combustion engine and each of said pump chambers being adjoined by a displacing body being displaceable to and fro over a pump stroke between two stops, said pump stroke being adjustable by means of control means in that each displacing member is displaceable to and fro between two common stops adjustable by means of control means. I

The mentioned and other features of the invention will be elucidated in the following description with reference to a drawing.

In the drawing each figure schematically shows a preferred embodiment of the injector according to the invention:

FIG. 1 shows a perspective view of an injector connected to a conventional four-cylinder four-stroke combustion engine;

FIG. 2 shows an axial section of a further developed injector connected to a four-cylinder four-strokecombustion engine, and

FIG. 3 and 4 each a side view of an injector of the type shown in FIG. 2, destinated for, but differently connected to a six-cylinder four-stroke combustion engme.

The parts shown in FIGS. 1, 2 and 3 which are provided with the same reference numbers have a same function.

The four-cylinder four-stroke combustion engine of FIG. 1 comprises a cylinder block 1 with the cylinders 20, 2b, 2c and 2d. The ignition takes successively place in the cylinders 2a, 2c, 2d and 2b. just as in the conventional four-cylinder four-stroke combustion engine during each two revolutions. The cylinder 2a is provided with the conventional parts such as ignition plug 4a, inlet valve 5a, exhaust valve 6a, piston 7a, driving rod 8a, crank 9a of a crank shaft 9 and with an air inlet branch 10a of an air inlet manifold 10. According to the invention a fuel pump 3a of an injector 3 is provided for the cylinder 20. The other cylinders 21; 2d are provided with corresponding parts and fuel pumps 3b 3d respectively. i

This'combustion engine further comprises a fuel tank 11 for receiving fuel, particularly petrol, and a main fuel pump 12 connected to the fuel tank 11, said pump 12 delivering fuel, e.g., under a pressure of l ato, to a fuel supply 13 of the injector 3. The fuel pump 3d shown in FIG. 1 delivering fuel to a fuel inlet 14d of the cylinder 2d, comprises a displacing member 15d constituted by a plunger, which adjoins a pump chamber 16d and two motor chambers 17d and 18d. The pump chamber 16d is connected to the fuel supply 13 via an inlet valve 24d which opens at an initial pressure of 0,6 ato against spring pressure of a spring 25d and is connected to a fuel exhaust 37d via an exhaust valve 27d which opens at an initial pressure of 1,5 ato against pressure of a spring 26d, said fuel exhaust 37d commuengages at each of the two sides of the pump chamber 16d a stop 36 resp. 22 which are common for all displacing members 15a, 15b, 15c and 15d. The motor chambers 17d and 18d are provided with connections 34d resp. 23d, said motor chambers 17d and 18d being connected through said connections 34d resp. 23d and through a narrow conduit'35d resp. 30d to the combustion cylinder 2a resp. 2d. The fuel pumps 3a, 3b and 3c are constructed and connected identically, with the understanding that the connections 34a, 34b, 340, 23a, 23b and 230 are connected to the combustion cylinders 2d, 2c, 2b, 2a 2b resp. 2c. This connection is such that the motor chambers 17d come under compression pressure of cylinder 2a and the displacing member 15d makes its pump stroke, while or shortly before a fuel air mixture is sucked into the cylinder 2d. During compression in combustion cylinder 2d the displacing member 15d is retracted over-the pump stroke under the oppo-- site influence of the pressure in the pump chamber 18d. Each of the two common stops 36 and-22 consists of a cam mounted swingable in bearings 33 and adjusted via an arm 46. The cam 36 is adjusted by a piston 32 moving in a cylinder 31 under the influence of the pressure prevailing in the inlet mainfold 10, said presure operating against the pressure power of the pressure spring 41. With decrease of the pressure in the inlet. manifold 10 by adjustment of the valve 38 by means of the throttle pedal 39 of a car, the quantity of air supplied into the combustion cylinders 2a 2d decreases, while than by reduction of the pump stroke adjusted by means of the cam 36, also the output of each pump 3a.

- 3d is reduced correspondingly and in exactly uniform amounts. The common stop 22 is adjustable under the influence of a barometer 43 correcting the pump stroke for compensating the pressure variations in the air entering the inlet manifold and under the influence of an electromagnet 44, which is excited during starting operation of the combustion motor for enlarging the output of the injector 3.

In order to prevent, that the fuel pump 3d is overheated, the conduit 35d is cooledby means of the air sucked in by the motor via the inlet manifold 10 and the conduit 35d is narrow.

The four-cylinder four-stroke combustion engine of FIG. 2 comprises a cylinder block 1 with the cylinders 2a, 2b, 2c and 2d. The ignition successively takes place in the cylinders 2a, 20, 2d and 2b just as in the conventional four-cylinder four-stroke combustion engine, during each two revolutions.

In FIG. 2 the pumps 3a 3d are positioned in series instead'of parallelly, while the displacing members a and 15b are combined to one displacing element 40):, as well as the displacing members 150 and 15d to a displacing element 40y. These displacing elements 40x and 40y are positioned in line between two adjustable common stops 22 and 36 which are wedge shaped instead of cam shaped, but for the rest said stops are adjusted as in FIG. 1 by the same control means 32, 31, 41 and 43, 44.

In that the movement sequence of the displacing members is determined by positioning them in line, the motor chambers 17a, 17b, 17c, 17d, 18a, 18b, 18c and 18d of the injector 3 are connected to the combustion engine in another way, viz. to cylinders 2d, 20, 2b, 2a, 2c, 2d, 2a and 2b respectively. It is to be remarked that the motor chambers 18a, 18b, 18c and 18d are constituted by chambers 17b, 17a, 17d resp. 170.

By cyclic movement of the displacing elements 40x and 40y the common stops 22 and 36 by turn will be unloaded from force'in axial direction, resulting in that adjustment of said stops is possible with minimum power, so that the adjustment accuracy is improved. In order to reduce the disadvantage of the irregular division of'the time of two motor revolutions in periods for the movement of the displacing elements 40x and 40y, and in order to obtain a fuel pumpmore suitable for meeting high numbers of revolutions, the displacing elements 40.x and 40y are preferably positioned parallelly and closely to each other between the two adjustable common stops 22 and 36, as the movement of the displacing elements 40x and 40y can be divided more reg ularly over the motor cycle, than in case of alignment in series, as shown in FIG. 2. The parallel position of the displacing elements 40x and 40y obtained in this way also has the advantage that the stops 22 and 36 during a period of the motor cycle are unloaded from axial force, resulting in less required adjustment power, with regard to the parallel position as shown in FIG. 1.

FIG. 3 shows an injector 3 of the type of FIG. 2, with the understanding that the injector of FIG. 3 is destinated for and connected to a six-cylinder four-stroke combustion engine with cylinders 2a, 2b, 2c, 2d, 2e and 2fwith the ignition sequence a, e, c,f, b, and d. The fuel pumps 3a, 3d, 32, 3b, 3c and 3f are positioned in the mentioned sequence in one and the same line between adjustable stops 36 and 22, whereby the displacing members 15a and 15d are combined to a displacing element 40u, the displacing members l5e and 15b to a displacing element 40v and the displacing members and 15f to a displacing element 40w.

The motor chambers 18a, 18d, 18e, 18b, 18c and 18], constituting the motor chambers 17d, 17a, 17b, 17e, 17f and respectively as well, are connected to the combustion cylinders 20, 2f, 2e, 2b, 2a and 2d respectively.

The operation of the injector of FIG. 3 is as follows.

As a result of the ignition sequence a, e, c, f, b and d motor chambers 180, 182, 18a, 18d, 18b and 18fare excited successively per combustion cycle, so that successively: displacing element 40w moves to the right to the position, as shown in FIG. 3, against stop 22, displacing element 40v moves to the right against displacing element 40w, displacing element 40u moves to the right against displacing element 40v, displacing element 40u moves to the left against stop 37, v displacing element 40v moves to the left against displacing element 40u, and displacing element 40w moves to the left against displacing element 40v, 7 whereby successively every time at the beginning of an inlet stroke fuel is injected into the air inlet branches 10f, 10b, 10d, 10a, 10a and l0fof combustion cylinders V FIG. 3, with a six-cylinder four-stroke combustion engine of an injector 3 the parts, as schematically shown in FIG. 4, can be in series in the following sequence:

stop 36, fule pumps 3d, 3b, 3a, 3f, 3e and 3c and stop 22, wherebythe motor chambers 18d, 18b, 18a, 18f, l8e and are connected to combustion cylinders 2c, 2f, 2e, 2b, 2a and 2d resp. The injection takes place in the middle of the inlet stroke of the combustion cylinder concerned.

It is to be remarked, that the injector 3 ofthe type as shown in FIG. 2 can be so connected that the injection takes place at the end of the inlet stroke of the combustion cylinder concerned. I

In that the retraction of each of the displacing elements 15a 15f occurs under the opposite influence of the pressure of a motor chamber connected to a combustion cylinder, the conduits connected to thecombustion cylinders can be narrow, as a result of which little gas from the combustion cylinders enters into and leaves said conduits. As a result the. cooling of these conduits is easier, and the pollusion of these conduits and the danger for detonation are less.

In that the displacing elements 40u, 40v, 40w, 40x and 40y with each stroke pump fuel, the energy taken from the combustion cylinders'is used very useful.

Owing to positioning all displacing elements in series between two strokes, they have an equal pump stroke with certainty, the number of parts of the injector is reduced to a minimum and a compact structureof the injector is possible at low costs. As the strokes 22 and 36 with each motor cycle are freed entirely of the displacing members, they can be adjusted with small power with the aid of control means. I

With the four-cylinder combustion engine as well as with a six-cylinder combustion engine a parallel position of the displacing elements 40u, 40v and 40w between the common stops 22 and 35 is possible, whereby the movement cycle of the displacing elements 40a, 40v and 40w is divided regularly over motor cycles. 1

It is to be remarked, that the above mentioned displacing members instead of by means of gas taken from a combustion cylinder of the combustion engine, can be driven in another way, e.g., via a cam axis driving pistons of fluid cylinders, which are each connected with one of the above mentioned motor chambers.

I claim:

1. lnjector for delivering fuel to at least two fuel inlets of a combustion engine with at least two combustion cylinders, comprising at least two pump chambers, each of said pump chambers communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to a fuel inlet of the combustion engine and each of said pump chambers being adjoined by a displacing member being displaceable to and fro over a pump stroke between two stops, said pump stroke being adjustable by means of control means, each displacing member being displaceable to and fro between two common stops adjustable by means of control means.

2. Injector according to claim 1, wherein at least two pump chambers are positioned in line between said two common stops.

3. lnjectoraccording to claim 2 wherein the two displacing members of said two pump chambers positioned in line are rigidly connected to each other.

4. lnjector according to claim 1 wherein all displacing members are positioned in one and the same line between said two common stops, said displacing members being in engagement with each other.

5. lnjector according to claim 1 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.

6. lnjector according to claim 2 wherein all displacing members are positioned in one and the same line between said two common stops, said displacing members being in engagement with each other.

7. lnjector according to claim 3 wherein all displacing members are positioned in one-and the same line between said two common stops, said displacing members being in engagement with each other.

8. lnjector according to claim 2 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.

9. lnjector according to claim 3 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.

10. A fuel injection system comprising, in combination:

at least two fuel injection nozzles;

a fuel pump assembly comprising at least two fuel chambers disposed with their axes in a common plane, means for supplying fuel under low pressure to each chamber and including a check valve associated with each chamber to prevent back flow of fuel, a first fuel outlet conduit connecting one of said nozzles to one of said chambers and a second fuel outlet conduit connecting the other of said nozzles to the other of said chambers and each conduit including a check-valve responsive to pressure greater than said low pressure for passing fuel to the associated nozzle, a piston reciprocable in each fuel chamber, and drive means for urging said pistons periodically first in one direction and then in the opposite direction sequentially to receive low pressure fuel and to discharge fuel under high'pressure to a respective nozzle; and first stop means for positively limiting the movements of said pistons in one direction and second stop means for positively limiting the movements of said pistons in the other direction, first control means connected with said first stop means for moving said first stop means selectively to allow increased strokes of said pistons under engine starting conditions, and second control means connected with said second stop means for moving said second stop means selectively to increase and decrease the strokes of said pistons under varying conditions 0 engine load. 11. A fuel injection system as defined in claim 10 wherein there are four injection nozzles, four fuel chambers all connected to said means for supplying fuel under low pressure and individually connected to said nozzles, four pistons, said fuel chambers having their axes disposed in said common plane, and said first and second stop means each being a unitary device whereby similarly to limit the positions of all of said pistons.

12. In a fuel injection system, the combination of:

a cylinder block. assembly having a plurality of fuel I chambers therein, a'plurality of pistons reciprocable in said chambers and cooperatively arranged in pairs in which as one piston of each pair moves in one direction the other piston of each pair moves in the opposite direction whereby said one piston causes fuel to enter its associated fuel chamber while the other piston causes fuel to be ejected under high pressure from its associated chamber and vice versa for the reversals of said directions of movement,'drive means for. impositively urging said pairs of pistons backand forth in said directions; and

first stop means and second stop means for positively limiting the end points of the strokes of all of said pistons whereby similarly to define the amounts of fuel delivered thereby, and control means for selectively varying the positions of said first and second stop means correspondingly to vary said amounts of fuel delivered. 7

13. In a fuel injection system as defined in claim 12 wherein there are four pistons arranged in two pairs thereof.

14. In a fuel injection system as defined in claim 13 wherein said first stop means iscontrolled manually for fuel enrichment during starting and said second stop means is controlled to increase and decrease said amounts of fuel delivered in dependence upon varia- 

1. Injector for delivering fuel to at least two fuel inlets of a combustion engine with at least two combustion cylinders, comprising at least two pump chambers, each of said pump chambers communicating via an inlet valve with a fuel supply and via an exhaust valve with a fuel discharge to be connected to a fuel inlet of the combustion engine and each of said pump chambers being adjoined by a displacing member being displaceable to and fro over a pump stroke between two stops, said pump stroke being adjustable by means of control means, each displacing member being displaceable to and fro between two common stops adjustable by means of control means.
 2. Injector according to claim 1, wherein at least two pump chambers are positioned in line between said two common stops.
 3. Injector according to claim 2 wherein the two displacing members of said two pump chambers positioned in line are rigidly connected to each other.
 4. Injector according to claim 1 wherein all displacing members are positioned in one and the same line between said two common stops, said displacing members being in engagement with each other.
 5. Injector according to claim 1 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.
 6. Injector according to claim 2 wherein all displacing members are positioned in one and the same line between said two common stops, said displacing members being in engagement with each other.
 7. Injector according to claim 3 wherein all displacing members are positioned in one and the same line between said two common stops, said displacing members being in engagement with each other.
 8. Injector according to claim 2 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.
 9. Injector according to claim 3 wherein the displacing members are positioned in a plurality of lines parallel to each other between said two common stops, each line being provided with at least the displacing members of two pump chambers.
 10. A fuel injection system comprising, in combination: at least two fuel injection nozzles; a fuel pump assembly comprising at least two fuel chambers disposed with their axes in a common plane, means for supplying fuel under low pressure to each chamber and including a check valve associated with each chamber to prevent back flow of fuel, a first fuel outlet conduit connecting one of said nozzles to one of said chambers and a second fuel outlet conduit connecting the other of said nozzles to the other of said chambers and each conduit including a check valve responsive to pressure greater than said low pressure for passing fuel to the associated nozzle, a piston reciprocable in each fuel chamber, and drive means for urging said pistons periodically first in one direction and then in the opposite direction sequentially to receive low pressure fuel and to discharge fuel under high pressure to a respective nozzle; and first stop means for positively limiting the movements of said pistons in one direction and second stop means for positively limiting the movements of said pistons in the other direction, first control means connected with said first stop means for moving said first stop means selectively to allow increased strokes of said pistons under engine starting conditions, and second control means connected with said second stop means for moving said second stop means selectively to increase and decrease the strokes of said pistons under varying conditions of eNgine load.
 11. A fuel injection system as defined in claim 10 wherein there are four injection nozzles, four fuel chambers all connected to said means for supplying fuel under low pressure and individually connected to said nozzles, four pistons, said fuel chambers having their axes disposed in said common plane, and said first and second stop means each being a unitary device whereby similarly to limit the positions of all of said pistons.
 12. In a fuel injection system, the combination of: a cylinder block assembly having a plurality of fuel chambers therein, a plurality of pistons reciprocable in said chambers and cooperatively arranged in pairs in which as one piston of each pair moves in one direction the other piston of each pair moves in the opposite direction whereby said one piston causes fuel to enter its associated fuel chamber while the other piston causes fuel to be ejected under high pressure from its associated chamber and vice versa for the reversals of said directions of movement, drive means for impositively urging said pairs of pistons back and forth in said directions; and first stop means and second stop means for positively limiting the end points of the strokes of all of said pistons whereby similarly to define the amounts of fuel delivered thereby, and control means for selectively varying the positions of said first and second stop means correspondingly to vary said amounts of fuel delivered.
 13. In a fuel injection system as defined in claim 12 wherein there are four pistons arranged in two pairs thereof.
 14. In a fuel injection system as defined in claim 13 wherein said first stop means is controlled manually for fuel enrichment during starting and said second stop means is controlled to increase and decrease said amounts of fuel delivered in dependence upon variations in engine load.
 15. In a fuel injection system as defined in claim 12 wherein said first stop means is controlled manually for fuel enrichment during starting and said second stop means is controlled to increase and decrease said amounts of fuel delivered in dependence upon engine load. 